CVE-2026-23089: linux Use After Free

Vulnerability summary

CVE-2026-23089 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.4% of scored vulnerabilities.

Timeline

1. 04-02-2026
   PublishedVulnerability first disclosed.
2. 19-10-2026
   Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix use-after-free in snd_usb_mixer_free() When snd_usb_create_mixer() fails, snd_usb_mixer_free() frees mixer->id_elems but the controls already added to the card still reference the freed memory. Later when snd_card_register() runs, the OSS mixer layer calls their callbacks and hits a use-after-free read. Call trace: get_ctl_value+0x63f/0x820 sound/usb/mixer.c:411 get_min_max_with_quirks.isra.0+0x240/0x1f40 sound/usb/mixer.c:1241 mixer_ctl_feature_info+0x26b/0x490 sound/usb/mixer.c:1381 snd_mixer_oss_build_test+0x174/0x3a0 sound/core/oss/mixer_oss.c:887 ... snd_card_register+0x4ed/0x6d0 sound/core/init.c:923 usb_audio_probe+0x5ef/0x2a90 sound/usb/card.c:1025 Fix by calling snd_ctl_remove() for all mixer controls before freeing id_elems. We save the next pointer first because snd_ctl_remove() frees the current element.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.